1. Field of the Invention
The present invention is directed to a bore sighting apparatus and more specifically to a pair of detachable targets adapted to be secured adjacent the muzzle of the tube for aligning the pantel and elbow telescopes on a howitzer.
2. Prior Art
The principal method currently in use for sighting a large caliber gun such as an M110 self-propelled howitzer involves the use of a target set in front of the gun at some distance with the two sights on the gun focusing on the target in a particular manner. Such a sighting method is impractical and sometimes even impossible where the terrain is uneven and the wind and weather conditions are such as to prevent the carrying out of an accurate sighting procedure.
Another prior art method involves the use of a distant aiming point which should have well defined vertical and horizontal axes at least 1500 meters distant. Such a distant aiming point is not always available and the method is clearly unusable under adverse conditions involving fog or darkness.
U.S. Pat. No. 1,994,177, to Nolan, granted Mar. 12, 1935 is directed to a bore sighting apparatus for large caliber guns wherein a pair of collimators are secured parallel to each other on a collimator frame which in turn is mounted directly in the muzzle of the gun for aligning the two sighting telescopes adjacent the breech.
U.S. Pat. No. 43,319 to Maltby granted June 28, 1864 is directed to an ordinance sight which may be mounted adjacent the muzzle of a gun by means of an adjustable band extending about the circumference of the gun. This forward sight is used in conjunction with a rear sight which is mounted on the knob of the cascabel.